Skip to main content
AK16
Associate II
August 7, 2023
Question

STM32H750B-DK output pins don't work while using the display

  • August 7, 2023
  • 3 replies
  • 1193 views

Hi,

I am trying to make a relay driver with STM32H750DB-K, so I could switch the relays with toggle buttons on display, but I have a difficulty writing on digital pins.

When I don't generate code from TouchGFX (so starting from scratch) and just write on output pin E3 calling the function HAL_GPIO_WritePin(GPIOE, GPIO_PIN_3, GPIO_PIN_SET); in while function of main.c the voltage on pin E3 is set to 3.3V as expected. But when I generate a simple code with TouchGFX (just a toggle button) and write function HAL_GPIO_WritePin(GPIOE, GPIO_PIN_3, GPIO_PIN_SET); in while function of main.c (which is in TouchGFX folder) the voltage on pin E3 is 0V. I tried this on several pins, but it is always the same.

Is there something obvious that I am missing? Does anyone know the solution to this problem?

This topic has been closed for replies.

3 replies

RhSilicon
RhSilicon
Lead
August 7, 2023

Generic codes can access the entire Port, this way despite momentarily having the state change in the HAL_GPIO_WritePin() instruction right after the display routines can be accessing the port that was controlled via HAL_GPIO_WritePin().

So that this type of problem does not occur when accessing the port, it is necessary to use a mask so that only the desired pins (bits) are modified.

uint32 target_reg = GPIOA->ODR;
uint32 mask = (1<<5); // mask = 0x00000020 
target_reg = target_reg | mask;
uint32 target_reg = GPIOA->ODR;
uint32 mask = ~(1<<5); // mask = 0xFFFFFFDF 
target_reg = target_reg & mask;

Ref.: https://hackmd.io/@hrbenitez/158_2s2223_GPIO

RhSilicon
RhSilicon
Lead
August 7, 2023

I don't know if it can help in your case, but I found these videos about advanced debugging:

https://youtube.com/playlist?list=PLnMKNibPkDnEDEsV7IBXNvg7oNn3MfRd6

Smartembedded
Smartembedded
Associate
August 14, 2023

Perhaps the GPIO you try is later reconfigurated to be input or an alternate function.

Also check if \TouchGFX\target\TouchGFXGPIO.cpp happends to use your GPIO.

Terms & ConditionsAccessibility statement